Water Nitrate

AUS-ASC-CON-WNI General Low confidence

Benchmark Value

0.64 mg/L
Thresholds: Lower: —, Upper: 0.64
Direction: Lower is desirable ↓
Form: UpperThreshold

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 8 benchmarks together — the OptimalRange form drives the primary score, while 7 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary UpperThreshold Guard MaximumOnly Guard Point Guard MaximumOnly Guard MinimumOnly Guard MaximumOnly Guard UpperThreshold Guard

Evidence & Context

A much higher threshold of 0.64 mg NO3-N/L is indicated by updated toxicity data.4 This level is not protective of the specific oligotrophic character and biodiversity of alpine ecosystems, which would be altered at far lower concentrations.

Metric Definition:

Upper toxicological threshold for nitrate concentration protecting 99% of species in soft water.

Benchmark Definition:

Toxicological upper threshold for nitrate concentration in soft water alpine ecosystems.

Justification:

Based on updated toxicity data for 99% species protection in soft water.

Sources (1)

Preview of Toxicant default guideline values for aquatic ecosystem protection ..., accessed August 8, 2025
Toxicant default guideline values for aquatic ecosystem protection ..., accessed August 8, 2025 Journal

Toxicant default guideline values for aquatic ecosystem protection ...

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Preview of Characterising alpine peatland water quality on the Bogong High Plains, Victoria - Threatened Species Recovery Hub
Characterising alpine peatland water quality on the Bogong High Plains, Victoria - Threatened Species Recovery Hub
Direct Evidence Journal

Characterising alpine peatland water quality on the Bogong High Plains, Victoria - Threatened Species Recovery Hub

View Source
Preview of NSW alpine resorts environmental performance report 2020–21
NSW alpine resorts environmental performance report 2020–21
Direct Evidence Journal

NSW Alpine Resorts Environmental Performance Report 2020–21

View Source

Context

  • Region Australia
  • Biome Alpine and Subalpine Complex
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 17 Mar 2026

Notes

This threshold is much higher than ecological health thresholds and not protective of oligotrophic character.

Related Benchmarks

Other benchmarks in the AUS-ASC-CON-WNI family.

0.01 mg/L High
Conservation / Protected Natural Areas · Pristine Reference
MaximumOnly Active v1
— mg/L Moderate
Conservation / Protected Natural Areas · Pristine Reference
OptimalRange Active v1